Image source, InphoImage caption, Down will face Armagh in the Ulster semi-finals

Down produced a major Ulster Championship upset to knock holders Donegal out with a 3-21 to 1-21 victory in a captivating quarter-final played out in a feverish atmosphere at O'Donnell Park.

Fired up from the start, Down led 0-11 to 1-7 at the break despite Caolan McGonagle's goal for the hosts.

Daniel Guinness' goal helped Down stretch their lead out to five points early in the second half, and while Donegal chipped away at the deficit to sit level with 20 minutes left, Conor Laverty's side roared to the finish with Miceal Rooney and Rooney netting late on to leave the home side stunned.

Down will face Armagh in the Ulster semi-finals, while Donegal are left to rue on their wrecked bid for a hat-trick of provincial titles before the start of the All-Ireland series.